Question

[(64×33×2:4-500×2):2+5×a]-6×12+999:9=112

Answer 1

[(64×33×2:4-500×2):2+5×a]-6×12+999:9=112
[(2112×2:4-500×2):2+5×a]-6×12+999:9=112
[(4224:4-500×2):2+5×a]-6×12+999:9=112
[(1056-500×2):2+5×a]-6×12+999:9=112
[(1056-1000):2+5×a]-6×12+999:9=112
(56:2+5×a)-6×12+999:9=112
(28+5×a)-6×12+999:9=112
(28+5×a)-72+111=112
(28+5×a)-72=112-111
(28+5×a)-72=1
(28+5×a)=1+72
(28+5×a)=73
5×a=73-28
5×a=45
a=45:5
a=9